The sophisticated use of social media to organise growing gang activity is likely to have helped the orchestrated looting of this week's riots, Karen Buck, the Labour MP for Westminster North, said.

The government should launch an independent inquiry into the triggers for this week's events, focusing in part on the role of social media in the spread of gangs, she added.

There has been a widespread denial of the seriousness of gang culture in central London, she said. "The way that gangs have emerged very strongly in the past few years has been facilitated by the use of social media," she said, describing use of Facebook and instant messaging as essential in orchestrating gang-related activity.

"We are so behind the curve in understanding its impact. We have been talking about this and pressing for action for at least two years. The phenomenon of postcode gangs is relatively new. Previously it was concentrated in a few areas of London, Hackney and Lambeth, but there has been deep denial of how much things have spread," she said.

"In the last few years, there has been a real escalation of youth violence, mostly youth on youth, which is why adults have largely been unaware of it."

In the past year, she has dealt with gang-related beatings, shop fires, and the kidnapping of a 13-year-old. "I have struggled to get councils to take it sufficiently seriously. The Met has been reluctant to see this as a problem that has spread."

She has been particularly concerned by the growth of videos posted on YouTube and the Spifftv website, made by rival gangs in central London, with gang members performing hip-hop and rap songs, written about their area, filmed against the backdrop of local estates. Some of the videos are professionally and expensively produced; some have confrontational lyrics, threatening gangs in other areas.

A teenage boy in her constituency was kicked into a coma, and given what police described as "life-changing injuries", earlier this year, after appearing in a video for an opposing gang, she said.

In a parliamentary question in July, she asked the Home Office what assessment they had made "of the contribution of social media to gang culture and related youth violence"; the reply was: "There has been no formal assessment of the contribution of social media to serious youth violence."

"Almost the most heartbreaking element is to see the incredible skill that goes into making the music and videos that has then been directed towards confrontation and aggression," she said. "If we can channel that into more positive things that could be really exciting."

Jackie Rosenberg, who helps run the Paddington Development Trust, offering youth services in central London, said: "Five years ago, in the world of young people's services … if someone talked about kids being in gangs, the response would be 'you're exaggerating, these are just small groups of friends, there's no such thing as gang culture'. That wouldn't be the response now."

She added: "It starts with poverty, and poverty comes in many guises; the children are growing up in environments where they face multiple disadvantages. Hostility towards the police was also a driver, and social media made creating and disseminating a clear identity easier."